The invention relates in general to the process commonly characterized as banding of containers or other articles, in particular to the "transport" step of a dry (as opposed to wet) process and specifically to transporting a creased band by means of an internal mandrel, and to apparatus for performing such processes and steps.
Briefly, banding comprises steps of opening, transporting, cutting, positioning, and shrinking. In both wet and dry processes, the banding material is most commonly supplied as a roll of tubing. The edges of the flat, ribbon-like tubing form a pair of opposed creases. In a dry process, a length of tubing, referred to as a band, is customarily cut from the roll of material, opened or re-opened, and transported to and positioned on a container or article.
In a wet process, the material is kept wet at all times until shrunk and it is customary to cut a band only after the tubing has been transported from the material source and applied to the article. The invention of J. G. Aguilar and Harold B. Rice described, illustrated and claimed in U.S. Pat. No. 2,860,468 which issued Nov. 18, 1958, is an example of a wet process banding apparatus and method.
In a dry process, it is customary to first cut a band and then transport the band to the article. There are numerous dry process banding processes and apparatus which employ an internal mandrel for transporting and positioning a band, for example, the invention of S. T. Carter described and illustrated in U.S. Pat. No. 2,771,725, which issued Nov. 27, 1956, hereinafter Carter; the invention of E. R. Levy described and illustrated in U.S. No. 2,680,549, hereinafter Levy; and the invention of Rodley Cross and John Laessig described, illustrated, and claimed in U.S. Pat. No. 3,888,067 which issued June 10, 1975, hereinafter Cross-Laessig.
Levy employs an initial rotational transport movement and concludes with axial positioning movement as the band is placed onto an article. The Levy apparatus partially opens pre-cut bands and loosely positions an opened band onto a tapered mandrel at a zero degree start position on a wheel which rotates about a horizontal axis. The mandrel with the loosely applied band is indexed to an upward orientation (90 degrees) where the band is forced onto the mandrel to a position on the mandrel base of a diameter which fully opens and holds the band. No further operations are performed on the band as the wheel is indexed another ninety degrees to orient the band and mandrel at 180.degree., but when the wheel is indexed another ninety degrees, to a position 270.degree. from the start position, the band is axially stripped from the mandrel with a washer which is around the mandrel and the inside diameter of which is about the size of the mandrel base. The wheel carries four mandrels spaced ninety degrees apart. As previously indicated, the wheel is indexed in ninety degree increments. During normal operation, for each indexing step a band is loosely applied on the mandrel at the zero degree start position, another band is forced onto a mandrel at the ninety degree position to fully open the band, and a third band is stripped from a mandrel and positioned on an article at the two hundred seventy degree position. Mandrel and hence band transport movement is rotational and incremental until the band is stripped from the mandrel.
Carter transport movement is principally lateral. The Carter apparatus opens a band as it is cut from a continuous roll of material, laterally vacuum transports the partially opend band (the axis of which is vertical) to an overhead positioning mandrel-like guide, lowers the guide into the band, and then mechanically strips the band from the guide, again with a close fitting washer-like stripper. See FIGS. 18 through 22 and FIGS. 9 through 14 in particular.
In both Levy and Carter, virtually all of the band transport movement is non-axial and thus circuitous, although the final positioning movement in both is axial. Both Levy and Carter require non-axial circuitous transport apparatus which, although integrated with, are in addition to, the band positioning apparatus. In both, a significant part of the transport step is in a direction other than in a straight line between the source and destination of the material.
Cross-laessig also employs a combination of axial and non-axial transport and positioning. A band is cut, pneumatically partially opened and transported to one of a rotating wheel of mandrels. The pneumatic transport ends and mechanical indexed rotational transport on a mandrel then commences and continues until the band carrying mandrel is indexed over an article. The band is pneumatically axially stripped from the mandrel and positioned on the article.
An object of the invention is to provide a banding process which can be performed efficiently and economically.
Another object of the invention is a banding process which can be repetitively performed at a high rate of speed.
An additional object of the invention is a banding process which is economical to perform with multiple stations.
A specific object of the invention is a banding apparatus which is sufficiently light and compact to make it practical to incorporate a plurality of such apparatus as a single rotating structure to provide a high speed banding station which accepts articles to be banded from a single source of supply at a high rate of speed and delivers banded articles to a single output means at the same high rate of speed, specifically at a rate which is the individual apparatus speed multiplied by the number of apparatus of the station.
Another specific object of the invention is a banding apparatus which requires only a single mandrel.
A further object of the invention is a banding process which is efficient as well as fast.
Yet another object of the invention is a banding process in which a band is positively controlled during each step from cut-off of the band through positioning of the band on the article to be banded.
A still further object of the invention is a process in which a band is transferred along a straight line path directly from its source to an article to be bended.
An object of the invention is a process and means by which a force applied to open a tube has a significant component perpendicular to the tube axis and an insignificant component parallel to the tube axis to minimize resistance to feeding of the tube.
Yet another additional object of the invention is a banding apparatus for carrying out a process according to one or a combination of the foregoing objects.
Another object of the invention is an apparatus which provides transport of a band by means of a mandrel continuously aligned co-axial with and between the article to be banded and a source of supply of said band.
A further object of the invention is a banding apparatus mandrel having one end of a geometry which readily opens a tube of banding material without significantly opposing the linear feeding of the material.
An additional object of the invention is a banding apparatus mandrel having a truncated diamond geometry end for opening a tube of banding material.
An object of the invention is an apparatus which adds at least one crease to a flat ribbon tubing to provide a tube end which is normally open to facilitate feeding of the tube end onto the mandrel.
A further object of the invention is an apparatus which creases a tube with the same means necessary for other functions of the banding process.